INTRODUCTION:

The crystalline powder of tadalafil is white to off-white in color. It dissolves somewhat in methanol and somewhat in water. Tadalafil's chemical formula is C22H19N3O4, and its molecular weight is 438.4 g/mol. After oral treatment, tadalafil is quickly absorbed. It takes 30 to 120 minutes to attain the maximal plasma concentration. The cytochrome P450 enzyme system breaks down tadalafil in the liver. 17.5 hours is the elimination half-life. One PDE5 inhibitor is tadalafil. One of the enzymes that breaks down cGMP is PDE5. One chemical that is involved in erectile function is called cGMP. Tadalafil aids in boosting cGMP levels in the penis, which causes an erection, by preventing the breakdown of cGMP.

Table No 1: Drug Profile for Tadalafil

Drug Name	Tadalafil
Brand Name	Cialis
Class	Phosphodiesterase type 5 (PDE5) inhibitor
Indications	Erectile dysfunction, benign prostatic hyperplasia (BPH)
Dosage	2.5-20mg orally once daily
Contraindications	Heart disease, liver disease, kidney disease, nitrate Medications
Precautions	Use with caution in people with diabetes, high blood pressure, and bleeding disorders
Overdose	Symptoms may include headache, flushing, and upset stomach. Seek medical attention if you experience any of these symptoms.
Storage	Store at room temperature in a dry place
Structure
IUPAC	(2R,8R)-2-(1,3-benzodioxol-5-yl)-6-methyl-3,6,17-triazatetracyclo[8.7.0.03,8.011,16]heptadeca-1(10),11,13,15-tetraene-4,7-dione.

UV and first order derivative spectroscopy provide greater selectivity than common spectroscopy and offer powerful approaches for resolution of band overlapping. The aim of the present study is the development of simple, accurate and sensitive UV and first derivative spectroscopic methods for the determination of Tadalafil.

INSTRUMENTATION:

Using a Double beam Shimadzu UV/Visible spectrophotometer, spectroscopic analysis was performed. In quartz cuvettes with a 1cm matched cell, zero order absorption spectra were obtained spanning the 200–400 nm wavelength range against a solvent blank. The first order derivative spectra across the 200–400nm range were acquired for every solution. A Shimadzu UV visible spectrophotometer equipped with 1cm matched quartz cells was used for all measurements. Every solution was made from scratch using pure water.

PREPARATION OF STANDARD STOCK SOLUTIONS:

Methanol was used to create standard tadalafil stock solutions. Methanol was added to a suitable volume of standard stock solution to achieve a concentration of 100 micrograms/mL of tadalafil. These solutions were further diluted in distilled water to provide conventional linearity concentrations for tadalafil in the range of 20–120 micrograms/mL.

SAMPLE PREPARATION:

Twenty tablets in all were precisely weighed and ground into a powder in a mortar. A 50mL volumetric flask was filled with precisely weighed amounts of the powdered tablets equal to 50mg. 30 milliliters of methanol were used to dissolve the weighed powder. After that, 50mL of methanol was added, properly mixed, and shaken for ten minutes. To achieve the desired concentration, the solution was diluted with distilled water solvent after passing through Whatman No. 42 filter paper and discarding a few milliliters of the filtrate.

Tadalafil working standard solutions were analyzed in order to create calibration curves. Every concentration was examined three times. Spectra of UV absorption were captured. Plotting the calibration curve involved using the Y axis for absorbance and the X axis for concentrations. The equation Y = mx + b, where m is the slope and b is the intercept, expresses the relationship between drug concentration (x) and its related absorbance (y).

Table No 2: Calibration Data for Tadalafil

Sr No	Concentration (micro gram/ml)	Absorbance
1	20	0.9
2	40	1.7
3	60	2.6
4	80	3.5
5	100	4.4
6	120	5.4

Fig no 1 standarad calibration curve

Selection of Wavelength:

The stock solution of concentration 10μg/ml was scanned over the range of 200–400nm and from recorded spectra the wavelength selected was 284nm

Fig No 2: Uv Spectra for Tadalafil

Fig no 3-FTIR Spectra for tadalafil

No.	Functional group (s)	Characteristic Absorption (s) range (cm^-1)	Identified in this study (cm^-1)
1	Aromatic C-H stretch	2950-2850	2918.53
2	C=C bond	1700-1500	1427-59
3	N-H stretch	3500-3300	3317.06
4	Benzene C=C Bond	1600-1500	1645.36
5	C=O Stretch	1750-1680	1675.45

METHOD B:

Tadalafil working standard solutions were analyzed in order to create calibration curves. Every concentration was examined three times. absorption of UV light. Spectrum underwent derivatization. Tadalafil's first derivative amplitude values (D1) were measured. Plotting the calibration curve involved taking the concentrations on the X axis and the first derivative values (D1) on the Y axis. The equation Y=mx+b, where m is the slope and b is the intercept, expresses the relationship between drug concentration (x) and its associated first derivative value (D1) value (y).

SAMPLE ANALYSIS:

Applicability of the proposed methods for the UV Spectrophotometric estimation Tadalafil was studied by assay of commercial tablets. The results obtained are given in Table no 4

RESULT AND DISCUSSION:

Table 3 summarizes the results of the calculations of the optical features, such as absorption maxima and Beer's law limitations, and the regression characteristics, such as slope (b), intercept (a), correlation coefficient (r), and standard error.

Table no 3: Optical characteristics

Parameter	UV Spectroscopy	Derivative spectroscopy
Wavelength	284 nm	284 nm
Beer’s law limit (micro gram/mL)	20-120 micro gram/mL	20-120 micro gram/mL
Slope(m)	0.045	0.3028
Intercept	0.06667	0.1530
(Y = mx + b), where m is slope and b is intercept.	Y=0.045X -0.0667	Y=0.3028 +0.1530
Correlation coefficient (r)	0.9991	0.9994

Recovery experiments were conducted by adding a known quantity of medication to a pre-analyzed sample, and the percentage recovery was computed in order to examine the precision and repeatability of the suggested approach. Table 4 presents the findings. The obtained results are consistent with the label clam.

For the estimation of tadalafil, two quick, easy, and precise UV and first derivative spectroscopic techniques have been developed. Both of these techniques have been effectively used to determine the medication in tablet dose forms. In quality control labs, these might be helpful for routine drug analyses.

Table no 4: assay and recovery

Tablet	Lable claim	Amount founded by proposed method	% Amount founded by proposed method	% Recovery by proposed method
cialis	20 mg	19.80 mg	99.10	99.45

ACKNOWLEDGEMENT:

Authors are thankful to the Department of Pharmaceutical Chemistry, Shri Sureshdada Jain College of Pharmacy Jammer for providing the instrumentation and laboratory facilities.

CONCLUSION:

In this study a simple, rapid, sensitive, accurate and precise UV spectrophotometric method for the determination of tadalafil in bulk and pharmaceutical formulation has been developed and validated. It was found that the common excepients present in the formulation did not interfere with the proposed method and can be used for the routine quality control analysis of tadalafil in bulk as well as in tablet formulations In this study a simple, rapid, sensitive, accurate and precise UV spectrophotometric method for the determination of tadalafil in bulk and pharmaceutical formulation has been developed and validated. It was found that the common excepients present in the formulation did not interfere with the proposed method and can be used for the routine quality control analysis of tadalafil in bulk as well as in tablet formulations This work developed and validated a straight forward, quick, sensitive, accurate, and precise UV spectrophotometric method for determining the amount of tadalafil in pharmaceutical formulations and bulk. Tadalafil in bulk and tablet formulations can be routinely analyzed for quality control using the common excepients contained in the formulation, which did not interfere with the suggested procedure.

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Received on 18.12.2024 Revised on 11.01.2025

Accepted on 28.01.2025 Published on 28.02.2025

Available online from March 03, 2025

Asian J. Pharm. Res. 2025; 15(1):6-8.

DOI: 10.52711/2231-5691.2025.00002

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